stormwater/wetland pond construction … pond construction inspection checklist ... invert at proper...

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Stormwater/Wetland Pond Construction Inspection Checklist

Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE

SATISFACTORY/ UNSATISFACTORY

COMMENTS

Pre-Construction/Materials and Equipment Pre-construction meeting

Pipe and appurtenances on-site prior to construction and dimensions checked

1. Material (including protective coating, if specified)

2. Diameter

3. Dimensions of metal riser or pre-cast concrete outlet structure

4. Required dimensions between water control structures (orifices, weirs, etc.) are in accordance with approved plans

5. Barrel stub for prefabricated pipe structures at proper angle for design barrel slope

6. Number and dimensions of prefabricated anti-seep collars

7. Watertight connectors and gaskets

8. Outlet drain valve

Project benchmark near pond site

Equipment for temporary de-watering

Appendix F: Construction Inspection ChecklistsTools

New York State Stormwater Management Design Manual

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Appendix F

CONSTRUCTION SEQUENCE


COMMENTS

2. Subgrade Preparation Area beneath embankment stripped of all vegetation, topsoil, and organic matter

3. Pipe Spillway Installation Method of installation detailed on plans

A. Bed preparation

Installation trench excavated with specified side slopes

Stable, uniform, dry subgrade of relatively impervious material (If subgrade is wet, contractor shall have defined steps before proceeding with installation)

Invert at proper elevation and grade

B. Pipe placement Metal / plastic pipe

1. Watertight connectors and gaskets properly installed

2. Anti-seep collars properly spaced and having watertight connections to pipe

3. Backfill placed and tamped by hand under Ahaunches@ of pipe

4. Remaining backfill placed in max. 8 inch lifts using small power tamping equipment until 2 feet cover over pipe is reached


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Appendix F



COMMENTS

3. Pipe Spillway Installation Concrete pipe

1. Pipe set on blocks or concrete slab for pouring of low cradle

2. Pipe installed with rubber gasket joints with no spalling in gasket interface area

3. Excavation for lower half of anti-seep collar(s) with reinforcing steel set

4. Entire area where anti-seep collar(s) will come in contact with pipe coated with mastic or other approved waterproof sealant

5. Low cradle and bottom half of anti-seep collar installed as monolithic pour and of an approved mix

6. Upper half of anti-seep collar(s) formed with reinforcing steel set

7. Concrete for collar of an approved mix and vibrated into place (protected from freezing while curing, if necessary)

8. Forms stripped and collar inspected for honeycomb prior to backfilling. Parge if necessary.

C. Backfilling

Fill placed in maximum 8 inch lifts

Backfill taken minimum 2 feet above top of anti-seep collar elevation before traversing with heavy equipment


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Appendix F



COMMENTS

4. Riser / Outlet Structure Installation Riser located within embankment

A. Metal riser

Riser base excavated or formed on stable subgrade to design dimensions

Set on blocks to design elevations and plumbed

Reinforcing bars placed at right angles and projecting into sides of riser

Concrete poured so as to fill inside of riser to invert of barrel

B. Pre-cast concrete structure

Dry and stable subgrade

Riser base set to design elevation

If more than one section, no spalling in gasket interface area; gasket or approved caulking material placed securely

Watertight and structurally sound collar or gasket joint where structure connects to pipe spillway

C. Poured concrete structure

Footing excavated or formed on stable subgrade, to design dimensions with reinforcing steel set

Structure formed to design dimensions, with reinforcing steel set as per plan

Concrete of an approved mix and vibrated into place (protected from freezing while curing, if necessary)

Forms stripped & inspected for Ahoneycomb@ prior to backfilling; parge if necessary


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Appendix F



COMMENTS

5. Embankment Construction Fill material

Compaction

Embankment

1. Fill placed in specified lifts and compacted with appropriate equipment

2. Constructed to design cross-section, side slopes and top width

3. Constructed to design elevation plus allowance for settlement

6. Impounded Area Construction Excavated / graded to design contours and side slopes

Inlet pipes have adequate outfall protection

Forebay(s)

Pond benches

7. Earth Emergency Spillway Construction Spillway located in cut or structurally stabilized with riprap, gabions, concrete, etc.

Excavated to proper cross-section, side slopes and bottom width

Entrance channel, crest, and exit channel constructed to design grades and elevations


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Appendix F


SATISFACTORY / UNSATISFACTORY

COMMENTS

8. Outlet Protection A. End section

Securely in place and properly backfilled

B. Endwall

Footing excavated or formed on stable subgrade, to design dimensions and reinforcing steel set, if specified

Endwall formed to design dimensions with reinforcing steel set as per plan

Concrete of an approved mix and vibrated into place (protected from freezing, if necessary)

Forms stripped and structure inspected for Ahoneycomb@ prior to backfilling; parge if necessary

C. Riprap apron / channel

Apron / channel excavated to design cross-section with proper transition to existing ground

Filter fabric in place

Stone sized as per plan and uniformly place at the thickness specified

9. Vegetative Stabilization Approved seed mixture or sod

Proper surface preparation and required soil amendments

Excelsior mat or other stabilization, as per plan


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Appendix F



COMMENTS

10. Miscellaneous Drain for ponds having a permanent pool

Trash rack / anti-vortex device secured to outlet structure

Trash protection for low flow pipes, orifices, etc.

Fencing (when required)

Access road

Set aside for clean-out maintenance

11. Stormwater Wetlands Adequate water balance

Variety of depth zones present

Approved pondscaping plan in place Reinforcement budget for additional plantings

Plants and materials ordered 6 months prior to construction

Construction planned to allow for adequate planting and establishment of plant community (April-June planting window)

Wetland buffer area preserved to maximum extent possible

Comments:


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Appendix F

Actions to be Taken:

New York State Stormwater Management Design Manual Appendix F

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Infiltration Trench Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector:



COMMENTS

1. Pre-Construction Pre-construction meeting

Runoff diverted

Soil permeability tested

Groundwater / bedrock sufficient at depth

2. Excavation Size and location

Side slopes stable

Excavation does not compact subsoils

3. Filter Fabric Placement Fabric specifications

Placed on bottom, sides, and top


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COMMENTS

4. Aggregate Material Size as specified

Clean / washed material

Placed properly

5. Observation Well Pipe size

Removable cap / footplate

Initial depth = feet

6. Final Inspection Pretreatment facility in place

Contributing watershed stabilized prior to flow diversion

Outlet

Comments:


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Infiltration Basin Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector:


SATISFACTORY/

UNSATISFACTORY

COMMENTS 1. Pre-Construction Runoff diverted

Soil permeability tested

Groundwater / bedrock depth


Side slopes stable


3. Embankment Barrel

Anti-seep collar or Filter diaphragm

Fill material


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COMMENTS

4. Final Excavation Drainage area stabilized

Sediment removed from facility

Basin floor tilled

Facility stabilized

5. Final Inspection Pretreatment facility in place

Inlets / outlets

Contributing watershed stabilized before flow is routed to the factility

Comments: Actions to be Taken:


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Sand/Organic Filter System Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE


COMMENTS

1. Pre-construction Pre-construction meeting Runoff diverted

Facility area cleared

Facility location staked out


Side slopes stable

Foundation cleared of debris

If designed as exfilter, excavation does not compact subsoils

Foundation area compacted

3. Structural Components Dimensions and materials

Forms adequately sized

Concrete meets standards

Prefabricated joints sealed

Underdrains (size, materials)


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COMMENTS

4. Completed Facility Components

24 hour water filled test

Contributing area stabilized

Filter material per specification

Underdrains installed to grade

Flow diversion structure properly installed

Pretreatment devices properly installed Level overflow weirs, multiple orifices, distribution slots

5. Final Inspection Dimensions

Surface completely level

Structural components

Proper outlet

Ensure that site is properly stabilized before flow is directed to the structure.


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Bioretention Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector:



COMMENTS


Runoff diverted

Facility area cleared

If designed as exfilter, soil testing for permeability



Lateral slopes completely level

If designed as exfilter, ensure that excavation does not compact susoils.

Longitudinal slopes within design range


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COMMENTS

3. Structural Components Stone diaphragm installed correctly

Outlets installed correctly

Underdrain Pretreatment devices installed

Soil bed composition and texture 4. Vegetation Complies with planting specs

Topsoil adequate in composition and placement

Adequate erosion control measures in place

5. Final Inspection Dimensions

Proper stone diaphragm

Proper outlet

Soil/ filter bed permeability testing

Effective stand of vegetation and stabilization

Construction generated sediments removed

Contributing watershed stabilized before flow is diverted to the practice


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Open Channel System Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector:



COMMENTS


Runoff diverted



Side slope stable

Soil permeability

Groundwater / bedrock

Lateral slopes completely level

Longitudinal slopes within design range


3. Check dams Dimensions

Spacing

Materials


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COMMENTS

4. Structural Components Underdrain installed correctly

Inflow installed correctly

Pretreatment devices installed

5. Vegetation Complies with planting specifications

Topsoil adequate in composition and placement

Adequate erosion control measures in place

6. Final inspection Dimensions

Check dams

Proper outlet

Effective stand of vegetation and stabilization

Contributing watershed stabilized before flow is routed to the factility

Comments:


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